Refactors user_scripts into checks (lua)

scripts/plugins/alerts/system/too_many_drops/checks/interface/too_many_drops.lua

@@ -0,0 +1,69 @@
+--
+-- (C) 2019-21 - ntop.org
+--
+
+local alerts_api = require("alerts_api")
+local checks = require("checks")
+local alert_consts = require("alert_consts")
+
+local script
+
+-- #################################################################
+
+local function check_interface_drops(params)
+  local alert_consts = require "alert_consts"
+  local info = params.entity_info
+  local stats = info.stats_since_reset
+  local threshold = tonumber(params.check_config.threshold)
+  local drop_perc = math.min(stats.drops * 100.0 / (stats.drops + stats.packets + 1), 100)
+  
+  local alert = alert_consts.alert_types.alert_too_many_drops.new(
+    stats.drops,
+    drop_perc,
+    threshold
+    )
+
+  alert:set_score_error()
+  alert:set_granularity(params.granularity)
+
+  if((stats.packets > 100) and (drop_perc > threshold)) then
+    alert:trigger(params.alert_entity, nil, params.cur_alerts)
+  else
+    alert:release(params.alert_entity, nil, params.cur_alerts)
+  end
+end
+
+-- #################################################################
+
+script = {
+  -- Script category
+  category = checks.script_categories.system,
+
+  default_enabled = true,
+  default_value = {
+    -- "> 5%"
+    operator = "gt",
+    threshold = 5,
+  },
+
+  -- This script is only for alerts generation
+  is_alert = true,
+
+  hooks = {
+    min = check_interface_drops,
+  },
+
+  gui = {
+    i18n_title = "show_alerts.interface_drops_threshold",
+    i18n_description = "show_alerts.interface_drops_threshold_descr",
+    i18n_field_unit = checks.field_units.percentage,
+    input_builder = "threshold_cross",
+    field_max = 99,
+    field_min = 1,
+    field_operator = "gt";
+  }
+}
+
+-- #################################################################
+
+return script